問題？
1、如何在程式碼中獲取控制元件在佈局檔案中寬、高的值，
2、並修改其大小即修改控制元件的顯示比例？

下面用Imageview控制元件舉例來實現此過程。
程式碼如下：

public class GetWidgetSize extends Activity
{
	int imageOriginalHeight = 0;
	int imageOriginalWidth = 0;
	boolean firstFlag = true;
	ImageView image = null;

	public void onCreate(Bundle savedInstanceState)
	{
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);

		image = (ImageView) findViewById(R.id.image);
		/*
		 * 通過setLayoutParams(new LinearLayout.LayoutParams())來還原佈局中設定的高度，寬度
		 */
		Button getBtn = (Button) findViewById(R.id.button1);
		getBtn.setOnClickListener(new OnClickListener()
		{
			public void onClick(View arg0)
			{
				image.setLayoutParams(new LinearLayout.LayoutParams(
						imageOriginalWidth, imageOriginalHeight));

			}
		});
		/*
		 * 通過setLayoutParams(new LinearLayout.LayoutParams())來設定控制元件顯示的大小
		 */
		Button setBtn = (Button) findViewById(R.id.button2);
		setBtn.setOnClickListener(new OnClickListener()
		{
			public void onClick(View arg0)
			{
				image.setLayoutParams(new LinearLayout.LayoutParams(
						LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));

			}
		});

		/*
		 * 通過這種方法獲取image控制元件在手機裡面顯示出來的高度和寬度
		 */

		ViewTreeObserver vto = image.getViewTreeObserver();
		vto.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener()
		{

			public void onGlobalLayout()
			{

				if (firstFlag == true)
				{
					firstFlag = false;
					imageOriginalHeight = image.getMeasuredHeight();
					imageOriginalWidth = image.getMeasuredWidth();
					System.out.println("imageHeight=" + imageOriginalHeight
							+ "  imageWidth==" + imageOriginalWidth);
				}
			}
		});
	}
	/*
	 * 重寫選單鍵，退出程式
	 */
	public boolean onCreateOptionsMenu(Menu menu)
	{
		super.onCreateOptionsMenu(menu);
		MenuItem item = menu.add(Menu.NONE, Menu.NONE, Menu.NONE, "Exit");
		item.setOnMenuItemClickListener(new MenuItem.OnMenuItemClickListener()
		{
			public boolean onMenuItemClick(MenuItem item)
			{
				System.exit(0); 
				return true;
			}
		});
		return true;
	}
}
 

		Display display = getWindowManager().getDefaultDisplay();
		int height = display.getHeight();
		int width = display.getWidth();